Field of the Invention
The present invention relates to a lithography technique.
Description of the Related Art
An imprint technique is a technique capable of forming (transferring) a nanoscale pattern. An imprint apparatus using the technique is attracting attention as one of lithography apparatuses for mass-producing magnetic storage media and semiconductor devices. The imprint apparatus forms a pattern of an imprint material on a substrate (silicon wafer, glass plate, or the like) by curing the imprint material while the imprint material on the substrate and an original (mold) are in contact with each other, and then separating (releasing) the original from the cured imprint material.
In an imprint apparatus or semiconductor exposure apparatus, it is necessary to grasp the replacement time or cleaning time of an original. Japanese Patent Laid-Open No. 2011-017914 discloses a method of estimating the deterioration state of a photo mask as an original using a photo mask inspection apparatus in an exposure apparatus.
However, even if the deterioration state is estimated using such method, the productivity may decrease. If, for example, an original reaches its use limit during lot processing, the lot processing is interrupted to start an operation of replacing the original. A decrease in productivity caused by such original replacement operation cannot be neglected.
Furthermore, if lot processing is interrupted to replace an original during the lot processing, a manufacturing error of a product may fail outside an allowable range due to a change in apparatus state caused by the interruption. Especially in a lithography apparatus in which one chamber accommodates two or more pattern transfer units, when an original is replaced only in a specific transfer mechanism (a pattern transfer unit), variations in the same lot may fall outside the allowable range, thereby decreasing the product yield.